This project is designed to customize the educational and research activities for Dr. Sangeeta Ray to achieve two major goals. The immediate goal is for Dr. Ray to expand her current research program in the targeted imaging of prostate cancer. Specifically, she will develop a new generation of imaging agents for the prostate- specific membrane antigen (PSMA) that will employ modalities and techniques not previously described. PSMA is an attractive target for the imaging and therapy of cancer in general, as it is over-expressed not only in prostate cancer, but in most solid tumor neovasculature. The long-term goal is for Dr. Ray to acquire advanced biomedical research skills and knowledge that complement her skills as an inorganic chemist. The ultimate goal is for her to develop into an independent, interdisciplinary researcher in the area of cellular and molecular imaging of cancer. She will obtain further, formal training in cancer biology, pharmacology and ethics germane to conducting preclinical and translational research. This program will be heavily weighted toward gaining expertise regarding the biology and pharmacology of imaging - particularly using magnetic resonance (MR)-based approaches under the mentorship of two internationally recognized scientists, Drs. Martin Pomper and Zaver Bhujwalla at Johns Hopkins University. Dr. Ray will develop PSMA-targeted multimodal contrast agents (CAs) followed by evaluation of these compounds through in vitro studies and in vivo MR imaging in relevant animal models. That will allow her to evaluate the in vivo binding specificity and pharmacokinetic profile of lead compounds en route to human studies. The combination of a multimodality imaging platform with therapeutic agents will also be explored for targeted drug delivery. The ABCG2 multi- drug resistance pump has become an important target in efforts to overcome chemotherapy resistance. Target tissue selective silencing of the ABCG2 gene via RNA interference could be a new, nontoxic strategy for treating prostate and other cancers. Accordingly, Dr. Ray will focus on the following specific aims: 1) to develop multimodality low molecular weight CAs that target PSMA. 2) To develop macromolecular CAs that target PSMA. 3) To develop PSMA targeted theranostic agents for PCa. This program will provide an excellent milieu in which the applicant - under close mentorship - can become deeply involved in MR imaging for cancer. Mentorship will be geared more toward biological issues to provide a well-rounded portfolio as she progresses toward independence in biomedical imaging research.